This invention relates to dc-to-dc power supplies for converting a single input voltage into two or more dc output voltages typically sense a single output voltage, usually the output voltage delivering the highest output power, and precisely regulate that output voltage while roughly regulating any additional output voltages. The precise regulation of a second or any number of additional output voltages is typically achieved by the use of dedicated individual series regulators, each output having its own series or pass regulator and a dedicated feedback amplifier. Post regulation using series or pass regulators is inefficient because of the energy lost in the series pass transistor and costly in terms of the additional parts required for each individual output voltage.